Core of transformers



Y. KATSUMOTO CORE OF TRANSFORMERS June 16, 1925. 1,542,144

Filed Feb. 21. 1922 Patented June 16, 1925.

UNITED STATES YASUTARO KATSUMOTO, 0F NISHI-K-U, OSAKA, JAPAN.

CORE OF TRANSFORMERS.

Application filed February 21, 1922. Serial No. 538,394.

To a]! whom it may concern:

Be it known that I, YAsU'rAno KA'rsUMo'ro, a subject of the Emperor ofJapan, residing at No, 36, 'lorishi1nzt-cl1o,' Nishi-ku, Osaka, Japan,have invented new and useful Improvements in a Core of Transformers, ofwhich the following is a specification.

This invention relates to improvements in transformer cores havingradially extend ing frames made of sheet iron, and has for its object toprovide a transformer having a large cooling surface, while at the sametime the quantity of iron and copper used in constructing the core iscomparatively small.

in the accompanying drawings a numberof examples of cores constructed inaccordance with the present invention are shown, and from which theprinciple of the invention will be readily understood. In said drawings:1

Fig. 1, is a perspective view of a trans former provided with a corehavingtwelve frames; 7

Fig. 2 is a plan view of the transformer shown in Fig. l; I

Figs. 3 and 4, are plan views of transformers having fifteen andeighteen frames respectively Figs. 5 and 7 are sectional plan views ofthe assembled inner legs of the frames forming the central pole of thecore of the transformers shown in Figs. 9. and 4 respectively Fig. 6 isa sectional plan view illustrating another form of central pole.

The same characters of reference designate the same parts in thedifferent figures of the drawings.

Referring to the drawings, each of the frames comprises an innervertical leg 0, an outer vertical leg I), and horizontal legs 0connecting the legs a and b at the upper and lower ends thereof, saidlegs together forming a tetragonal frame. The outer and connecting legsof the sections of the frame may be of any convenient form, providedthey are of the same area, but the inner legs are of rhombic formation.

The frames above described are arranged radially, the inner legs beingassembled side by side to form the central pole of the core,

as clearly shown in the drawings. The assembled inner legs may bedisposed in a singlelayer, or in two or more layers, according to thenumber of frames. The sec length of the coils.

tion of the pole thus formed is a regular hexagon. The frames may be soassembled that the inner legs form an opening at the center of the core,as shown in Fig. (3, or if preferred, the center portion may be solid,as shown in If'ig. T. In Figs. 2 and 3, the assembled legs form anopening at the center, but said opening is filled with a sheet iron core6. The connecting legs (2 may extend straight as shown in Fig. 2, butall, or some of thenrmay be curved along their sides as shown in Figs. 3and 4, when desired. The connecting legs attached to the inner layer ofthe central pole are disposed outside of those attached to the outerlayer of said pole, but all of the outer vertical legs 6 are distributedat the same distance from the center, that isto say, in a circle.-

Coils (Z are wound on the central pole of the core, as is well known intransformers having radial cores.

In the present invention, a sectional view of the central pole of thecore is a regular polygon, and the outer legs are divided into a numberof sections distributed almost all over the outer surface of the coils,and the laminations of iron comprising a single unit of the frame are ofthe same dimensions. Consequently, the mean length of the connectinglegs is reduced, and that of the inner legs may also be reduced. Becauseof this construction the core can be divided into a number of sectionsso that said core may readily be distributed almost over the entireouter surface of the coils. As a result of this disposition, thethickness of the outer legs may be greatly reduced while keeping therequired sectional area, thus effecting a considerable saving in thequantity of iron used in the construction of the transformer.

Furthermore, as the cross section of the assembled inner legs is aregular polygon, the coils may be wound thereon so as to form a circle.so that the mean length of the coilsmay be reduced. This saves aconsiderable quantity of copper in the total Moreover, the curvature ofthe coils being less sharp. not only is the operation of windingrendered very easy, but the insulation is not subject to injury by anynecessity for sharply bending the wire.

From the foregoing it will be seen that lit) large compared with itsvolume, which atfords etlective cooling of the tianstornzer thusconsiderably increasing the etl'iriency ot' the latter, while theweight, as well as the initial cost are materially reduced.

Having thus described my invention, what I claim is:

1. A transformer core, comprising a phlralit ol radially extending sheetiron frames ol uniform dimensions each hav' an inner vertical leg, anouter vertical itand a pair of horizontal legs imniectin 7 ends of saidvertical leg," the inner oi the frames being disposed in contiguousrelation in at least two layers and forming a central pole, thesectional torn: ol th in ner legs being rhonihic and the outer verticallegs disposed in a circle.

2. A transformer core comprising radiall v extending sheet iron framesof uniform dimensions each having an inner vertical leg, an outervertical leg, and a pair of horizontal legs connecting the ends of saidvertical legs, the inner legs of the frames being disposed in contiguousrelation in at least two layers and forming a central pole ot hexagonalsection, the sectional form of the inner legs being rhoinhic and theouter vertical legs disposed in a circle.

3. A transformer core, comprising radially extending sheet iron frames02'' unilorin dimensions, each having an inner vertical leg an outervertical leg and. a pair of hori zontal legs connecting the ends ol'said acrtical legs. said connecting legs being curred along their sides,the inner legs ol the frames being disposed in contiguous relation in atleasttwo layers and torining a central pole o't hexagonal section, the stional form of the inner le 's being rhoinhie and the outer verticaldisposed in a circle.

In testimony whereof l have signed my name to tl'iis-specification,

YASUTAR KAIS [U l )Tt).

